Hi!
I'm currently modifying my Rega Planet thanks to the advise provided on this -also excellent- site:
http://www.homecinema-fr.com/forum/viewtopic.php?t=29699595
Be carefull, it's in french!
I'm not an electronician, but I succeed to cleanely apply the suggestions that were given to me.
I've replaced the 100 µF Samwha capacitors which decoupled the output chip (Sanyo LA9216 - no datasheet avalaible, but doutbless a similar chip to the LA9215) by Black Gate BG 100µF/50V and the 47 µF one which decoupled the +5V Burr Brown PCM1710UDAC analog power supply by a similar Black Gate 470 µF/50V.
I have also changed the Samwha SG 100 µF output capacitors by cabled pairs of MKP Monacor 10µF + 82 nF MKS. All the ceramic capacitors on the PCCDAC board has been changed towards MKS, except for the 16.9344 MHz oscillator, which is now decoupled by 22 pF silvered mica caps.
Last, two 470 ohms series resistors on the ouput lines where replaced by 121+12.1 ohms.
Now, the sound has improved: more feel, more firmness in the bass (but no more power), more precise focalisation, and, more than all, no harshness. Perhaps the soundscape is now a bit to close from the auditor and sligthly less wide.
So, the mod succeed, but I wish to go a little further. Perhaps by changing caps of the power supply and some coupling caps in the output.
I have also a question: why do Rega put two 470 ohms serie resistors in each output line? That give an output impedance of 930 ohms across the audio band (mesurement of Stereophile).
The purpose of this resistors is quite a mystery to me and, also I reduce their values, I'd rather prefer know what about them.
Any idea?
Thanks.
I'm currently modifying my Rega Planet thanks to the advise provided on this -also excellent- site:
http://www.homecinema-fr.com/forum/viewtopic.php?t=29699595
Be carefull, it's in french!
I'm not an electronician, but I succeed to cleanely apply the suggestions that were given to me.
I've replaced the 100 µF Samwha capacitors which decoupled the output chip (Sanyo LA9216 - no datasheet avalaible, but doutbless a similar chip to the LA9215) by Black Gate BG 100µF/50V and the 47 µF one which decoupled the +5V Burr Brown PCM1710UDAC analog power supply by a similar Black Gate 470 µF/50V.
I have also changed the Samwha SG 100 µF output capacitors by cabled pairs of MKP Monacor 10µF + 82 nF MKS. All the ceramic capacitors on the PCCDAC board has been changed towards MKS, except for the 16.9344 MHz oscillator, which is now decoupled by 22 pF silvered mica caps.
Last, two 470 ohms series resistors on the ouput lines where replaced by 121+12.1 ohms.
Now, the sound has improved: more feel, more firmness in the bass (but no more power), more precise focalisation, and, more than all, no harshness. Perhaps the soundscape is now a bit to close from the auditor and sligthly less wide.
So, the mod succeed, but I wish to go a little further. Perhaps by changing caps of the power supply and some coupling caps in the output.
I have also a question: why do Rega put two 470 ohms serie resistors in each output line? That give an output impedance of 930 ohms across the audio band (mesurement of Stereophile).
The purpose of this resistors is quite a mystery to me and, also I reduce their values, I'd rather prefer know what about them.
Any idea?
Thanks.
A high output impedance is typical for Japanese-style CD-players. I guess it is for making the components utterly foolproof. Which is something that ties in with Rega's philosophy as well.
Two resistors in series because it is a T filter that with those small ceramic Cs filters incoming as well as outgoing HF garbage.
Do you have the datasheet of the 9215?
(Funny, I only modified my own Planet two days ago, and no time for listening yet. I did start this job because I have a boatload of Rubycon ZAs I have to find a use for.)
Two resistors in series because it is a T filter that with those small ceramic Cs filters incoming as well as outgoing HF garbage.
Do you have the datasheet of the 9215?
(Funny, I only modified my own Planet two days ago, and no time for listening yet. I did start this job because I have a boatload of Rubycon ZAs I have to find a use for.)
Attachments
rega mods...
hi,
you should change the masterclock - search elso kwak clock...
also change the rectifiers to schottkies - http://www.schuro.de/Daten/IR/11dq10.pdf
http://www.schuro.de/Daten/IR/31dq10.pdf
good luck
troels
hi,
you should change the masterclock - search elso kwak clock...
also change the rectifiers to schottkies - http://www.schuro.de/Daten/IR/11dq10.pdf
http://www.schuro.de/Daten/IR/31dq10.pdf
good luck
troels
Hello, Werner.
Yes, I have the datasheet of the LA9215 in PFD file, but this is not very detailed
Thanks for your explanation about T filter. Anyway, I come back to the 2x470 Ohms: it's better for the transients and the soundscape with my associated IC cables and preamp input impedance. I remove the costly BG from the +5V of the DAC and put again the previous cap : it did change anything.
Nice work you have done. What are the improvements and changes?
Yes, I have the datasheet of the LA9215 in PFD file, but this is not very detailed
Thanks for your explanation about T filter. Anyway, I come back to the 2x470 Ohms: it's better for the transients and the soundscape with my associated IC cables and preamp input impedance. I remove the costly BG from the +5V of the DAC and put again the previous cap : it did change anything.
Nice work you have done. What are the improvements and changes?
Guys,
owning a Planet too, i wanted to start some modifying.
a. SPINDLE
i split the wobbly spindle [with a junior handsaw blade]
the top half i secured with double-sided tape on the lid.
the remaining spindle/magnet is put by hand -upside down-
on the cd.
it gives less noise and more detail, firmer bass
b. LED-FILTER
next step is putting some blue-leds in the CD bay.
12v type with intgrated resistors, couple to a pot-meter and
a 12v transformer
did some testing already with blue led and watch-battery,
sound was impressive, but battery gone to soon
c. PRINTED CIRCUIT
surfing i found 3 threads:
1. acoustica.org.uk
2. homecinema-fr.com
3. audioasylum/tweaker's asylum/digital/ carlos' threads
4. the one i'm in now
in general they consist of the same:
change the clock
change capacitors
resistors
what i'm missing is a listing and a scheme
where is indicated where what is changed.
the pic's of werner are a start:
I can recognize that at C7 cap was changed to Rubycon ZA 35v 100Uf but that's about it.
schottky's: doe you mean that instead of 11DQ10 also the othe 3xx tyhpe can be used?
in other words can you provide more details?
owning a Planet too, i wanted to start some modifying.
a. SPINDLE
i split the wobbly spindle [with a junior handsaw blade]
the top half i secured with double-sided tape on the lid.
the remaining spindle/magnet is put by hand -upside down-
on the cd.
it gives less noise and more detail, firmer bass
b. LED-FILTER
next step is putting some blue-leds in the CD bay.
12v type with intgrated resistors, couple to a pot-meter and
a 12v transformer
did some testing already with blue led and watch-battery,
sound was impressive, but battery gone to soon
c. PRINTED CIRCUIT
surfing i found 3 threads:
1. acoustica.org.uk
2. homecinema-fr.com
3. audioasylum/tweaker's asylum/digital/ carlos' threads
4. the one i'm in now
in general they consist of the same:
change the clock
change capacitors
resistors
what i'm missing is a listing and a scheme
where is indicated where what is changed.
the pic's of werner are a start:
I can recognize that at C7 cap was changed to Rubycon ZA 35v 100Uf but that's about it.
schottky's: doe you mean that instead of 11DQ10 also the othe 3xx tyhpe can be used?
in other words can you provide more details?
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